/*
 * Copyright (C) 2011-2021 Intel Corporation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 */


#include "DigestUtils.h"
#include "OpensslHelpers/OpensslTypes.h"

#include <openssl/sha.h>

namespace intel { namespace sgx { namespace dcap { namespace crypto {

Bytes sha256Digest(const Bytes& bytes)
{
    auto ctx = crypto::make_unique(EVP_MD_CTX_new());
    const EVP_MD* md = EVP_sha256();
    Bytes hash(SHA256_DIGEST_LENGTH);
    uint32_t hashLen;
    if (ctx.get() != nullptr &&
        EVP_DigestInit_ex(ctx.get(), md, nullptr) == 1 &&
        EVP_DigestUpdate(ctx.get(), bytes.data(), bytes.size()) == 1 &&
        EVP_DigestFinal_ex(ctx.get(), hash.data(), &hashLen) == 1 &&
        hashLen == SHA256_DIGEST_LENGTH)
    {
        return hash;
    }
    return Bytes{};
}

}}}}
